The Archimedes screw is a well known device originally designed for the purpose of raising water. Such a device generally comprises a rotating broad-threaded screw or spirally bent tube positioned within an inclined hollow cylinder. The screw or tube is turned within and about the axis of the cylinder with the bottom of the cylinder immersed in the liquid to be raised and the top of the cylinder open. A portion of the liquid is then trapped between adjacent turns of the screw or tube as a result of the inclination of the supporting cylinder and the entrapped liquid is transported up the cylinder and discharged from the upper end of the cylinder.
The basic operation of the Archimedes screw has been known for thousand of years but its operation is difficult to illustrate graphically. It is an object of the present invention to provide a display apparatus which can clearly and conveniently illustrate the operation of an Archimedes screw.